How to get 55 mcg of selenium a day through a balanced diet

November 1, 2025 •

4 min read

For most healthy adults over 14 years old, the Recommended Dietary Allowance (RDA) for selenium is 55 micrograms (mcg) per day. Achieving this vital micronutrient target is simpler than you might think by incorporating a variety of selenium-rich foods into your daily meals.

Quick Summary

Achieving the recommended daily intake of 55 mcg of selenium is attainable by strategically choosing specific foods. Understand the best sources and how to combine them effectively for a balanced, nutrient-rich diet plan.

Key Points

Daily Target: The Recommended Dietary Allowance (RDA) for most adults is 55 mcg of selenium per day.
Top Sources: Excellent dietary sources include seafood (tuna, sardines), meat (pork, beef), and Brazil nuts.
Brazil Nut Precaution: Just one Brazil nut can provide more than the daily requirement, but intake should be moderated due to potential for toxicity.
Diet Over Supplements: Food sources are the safest way to meet your selenium needs, with supplements reserved for documented deficiencies.
Thyroid and Immunity: Selenium is crucial for thyroid hormone metabolism and maintaining a healthy immune system.
Varied Intake: Building a balanced diet with a mix of selenium-rich foods is a simple way to consistently achieve the 55 mcg target.

Why 55 mcg of Selenium is the Daily Target

Selenium is a trace mineral that is essential for human health, playing a crucial role in the body's physiological processes. It functions as an antioxidant, helping to protect cells from oxidative stress and damage caused by free radicals. Selenium is also vital for the proper functioning of the thyroid gland, which contains the highest concentration of this mineral in the body. Adequate selenium intake supports a healthy immune system, aids in reproductive health, and can help prevent cognitive decline. The RDA of 55 mcg for adults is the amount considered sufficient to meet the needs of nearly all healthy individuals in the population.

Top Dietary Sources of Selenium

The most effective way to reach your daily 55 mcg selenium goal is through diet, which is generally considered safe and effective. The amount of selenium in food can vary depending on the content of the soil where plants are grown, but animal products and seafood tend to have more consistent levels.

Seafood

Seafood is one of the most reliable and potent sources of dietary selenium. A single serving can often provide a significant portion of your daily requirement.

Yellowfin Tuna: A 3-ounce serving offers a substantial 92 mcg, which is well over the daily target.
Sardines (canned in oil): A 3-ounce serving provides 45 mcg, nearly fulfilling the daily need.
Shrimp: Cooked shrimp offers 42 mcg per 3-ounce serving.

Meats and Poultry

Pork: A 3-ounce serving of a broiled, bone-in pork chop contains 37 mcg.
Beef: Roasted beef steak (bottom round) and pan-fried beef liver both provide around 37 mcg and 28 mcg per 3-ounce serving, respectively.
Chicken and Turkey: A 3-ounce serving of roasted chicken (light meat) or boneless, roasted turkey offers 22 mcg and 26 mcg, respectively.

Other Sources

Brazil Nuts: These are an extremely rich source, with just one nut containing a massive average of 68–91 mcg. Due to this variability and high concentration, moderation is key to avoid excessive intake.
Eggs: One large hard-boiled egg contains about 15 mcg of selenium.
Grains and Beans: Cooked spaghetti offers 33 mcg per cup, while brown rice has 12 mcg per cup. One cup of canned baked beans provides 13 mcg.

Building a Daily Meal Plan

Achieving 55 mcg daily can be done by strategically combining foods throughout your day. Here are a few example combinations:

Option 1 (Seafood Focus): Breakfast: Scrambled eggs (1 egg = 15 mcg). Lunch: Turkey sandwich (3 oz turkey = 26 mcg). Dinner: 3 oz roasted beef steak (37 mcg). Total: 78 mcg, comfortably over the target.
Option 2 (Plant-Forward): Breakfast: Oatmeal (1 cup = 13 mcg). Lunch: A large salad with 1 oz of sunflower seeds (approx. 18 mcg). Dinner: 1 cup cooked spaghetti with marinara sauce (33 mcg + 4 mcg). Total: 68 mcg.
Option 3 (Simple & Quick): One Brazil nut (average 75 mcg) as a snack. This single item meets and exceeds the daily requirement for most adults, though it should be noted that the selenium content can vary significantly per nut based on the soil it grew in.

When to Consider Supplements

While dietary intake is the preferred method for getting selenium, supplements can be an option if your diet is restricted or if you have a documented deficiency. Supplements should be used with caution, as high doses can lead to toxicity, with the tolerable upper intake level (UL) for adults set at 400 mcg per day. Always consult a healthcare provider or a registered dietitian before starting any new supplement regimen. Excessive selenium intake can lead to adverse effects like hair loss, brittle nails, and gastrointestinal issues.

Conclusion: Achieving Your Selenium Goal

Getting 55 mcg of selenium a day is an achievable and important nutritional goal for maintaining overall health, particularly thyroid and immune function. By prioritizing a varied diet rich in seafood, lean meats, and nuts like Brazil nuts, you can easily meet your needs without resorting to supplements. Paying attention to your food choices and understanding portion sizes will empower you to reach your daily target effectively. For those with specific dietary concerns, consulting a professional can provide a tailored strategy to ensure adequate intake. For more comprehensive nutritional information, refer to authoritative sources like the NIH Office of Dietary Supplements.

Selenium-Rich Food Comparison


Food (Serving Size)	Selenium (mcg)	Notes
Brazil Nuts (1 nut)	~68–91	Content varies widely; use with caution.
Yellowfin Tuna (3 oz, cooked)	92	Excellent source; surpasses daily goal.
Sardines (3 oz, canned in oil)	45	Nearly meets the daily requirement.
Shrimp (3 oz, cooked)	42	Another strong seafood option.
Pork Chop (3 oz, broiled)	37	Solid contribution from lean meat.
Beef Steak (3 oz, roasted)	37	Good source from red meat.
Spaghetti (1 cup, cooked)	33	Significant grain-based source.
Egg (1 large, hard-boiled)	15	Easily incorporated into many meals.
Oatmeal (1 cup, cooked)	13	Simple, nutritious breakfast item.

Outbound Link: NIH Office of Dietary Supplements

Frequently Asked Questions

Symptoms of selenium deficiency can include fatigue, muscle weakness, a weakened immune system leading to frequent illness, hair loss, and mental fog. Severe, long-term deficiency can lead to heart conditions like Keshan disease.

While it is unlikely to get an overdose of selenium from a varied diet, it is possible by eating large quantities of foods exceptionally high in the mineral, such as Brazil nuts. Excessive, long-term intake can lead to toxicity, so moderation is key.

Yes, the amount of selenium in plant-based foods can vary widely depending on the selenium concentration of the soil where they were grown. Animal products, however, tend to have more consistent levels.

Due to the highly variable selenium content in Brazil nuts, just one large nut can often provide the entire 55 mcg daily requirement, and sometimes much more. You should eat them in moderation.

Selenium is essential for the function of the thyroid gland, which contains the highest concentration of the mineral in the body. It helps convert inactive thyroid hormone (T4) into its active form (T3).

Yes, vegetarians and vegans can get enough selenium, though it requires intentional food choices. Good sources include Brazil nuts, sunflower seeds, beans, lentils, and whole grains, though amounts can vary based on soil content.

Regularly exceeding the 400 mcg Tolerable Upper Intake Level (UL) can lead to selenium toxicity, known as selenosis. Symptoms include hair and nail brittleness or loss, skin rash, nausea, diarrhea, and in severe cases, nervous system problems.

Yes, selenium can interact with certain medications and supplements, including cholesterol-lowering drugs and chemotherapy agents. Always inform your healthcare provider about your intake of selenium, especially if you are taking supplements.